Shaft couplings of the type in which extruded or bar-shaped elastic and generally elastomeric elements serve to angularly couple a flange with a hub have in the past used coupling bodies of a generally cylindrical shape which are applied with radial prestress between the outer periphery of the hub and the inner periphery of the flange, i.e. the opening in the flange in which the hub is received.
Generally in such cases the inner periphery of the opening in the flange is a regular four-sided polygon (square) with the outer periphery of the hub forming a geometrically similar polygon which, however, is of smaller diameter (diagonal dimension). An angular offset between the hub and the polygon formed by the opening in the flange, usually to maintain symmetry an angular offset of 45.degree. in the case of four-sided polygons, results in pockets between the vertices of the outer polygon and the sides of the inner polygon.
The elastomeric coupling bodies are received in these pockets and are compressed between the surfaces of the hub and the surfaces adjacent the hub vertices of the corners of the outer polygon with a distortion depending upon the relative angular displacements of the hub and the coupling flange. These coupling bodies then act as torsion springs.
The relatively soft transmission of torque between the coupling flange and the hub through the elastomeric bodies has made the prospects for such coupling very promising, although in practice such couplings have not played a significant role in the marketplace, especially because of the difficulty in assembling the coupling with a shaft in the axial direction.
The hub can have a previously formed bore with a groove for the key which is to angularly connect the shaft with the hub. In the past it has been necessary to assembly the hub onto the shaft by hammering and this poses a problem since exact axial alignment of the flange usually requires that it be premounted on the driving member in exact axial alignment therewith before the shaft is hammered in place. The problems associated with this type of mounting have largely precluded use of the coupling.
Furthermore dismounting of the coupling has required special pullers to separate the shaft from the remainder of the coupling.